function s1_goto_dir() {

    cd "$1"

}



function s2_touch_empty_file_with_given_name() {

    touch "$1"

}



function s3_make_directories() {

    mkdir -p ./projects/{git/,backup/}

}



function s4_create_6_files() {

    touch ./projects/linux{1,2}_{centos,redhat,c_programming}

}



function s5_make_directories_in_git() {

    mkdir ./projects/git/linux{1,2}

}



function s6_move_files_to_dir_1_or_2() {

    mv ./projects/linux1* ./projects/git/linux1 && mv ./projects/linux2* ./projects/git/linux2

}



function s7_create_package_and_compress() {

    tar -czvf ./projects/backup/git.tar.gz ./projects/git

}



function s8_delete_dir_git() {

    rm -rf ./projects/git

}



function s9_recover_from_git_tar_gz_backup() {

    tar -zxvf ./projects/backup/git.tar.gz ./projects/

}



function s10_create_package_and_compress() {

    tar -jcvf ./projects/backup/git.tar.bz2 ./projects/git

}



function s11_find_and_sort_alphabetically_all_created_files_and_dirs() {

    find ./projects | sort

}


function s12_get_next_15_minutes_boundary() {

    date -d "@$(($(date +%s) - $(date +%s) % 900 + 900))" +"%Y-%m-%d_%H:%M:%S"

}




